[Serusers] can SER do network call forwarding?

[Juha Heinanen]

Adrian Georgescu writes:

 > A SIP provider has interconnect from incumbent PSTN operator (Cisco 
 > gateway) using SIP (SER installation). This provider has an E164  
 > number range placed in ENUM. The problem here is that when an ENUM 
 > number is resolved to a remote domain and the destination username is 
 > an alias on the remote domain, the provider proxy will pass the 
 > redirect back to gateway who in term makes the final call.

it is not a good idea to let the gw to process the redirect, since if
call is coming from pstn to a sip user and the sip user has redirect to
expensive 700 number, the gateway would need to pay for the new leg.
but as i tried to explained earlier, i don't think that it is a good
idea for the proxy to process it either, since again, who would pay for
the new leg if it would go to a 700 number?  legally the user who has
placed redirect in his or her sip phone cannot be charged for the
redirect.

 > This provider gets paid by the incumbent for terminating minutes on IP 
 > for those E164 numbers but as the proxy is not in the middle they do 
 > not know how much traffic their numbers generated for anything that is 
 > an alias. The problem in this case is accounting. The Proxy should stay 
 > in the middle of the dialog in this scenario so your function makes 
 > perfect sense.

the proxy would stay in the middle if the proxy is serving the domains
enum queries return.  so i don't quite understand your example.

 > This scenario is described very nice in this document.

it is not clear from the document, why the 302 can't go all the way to
A, i.e., what the benefit is for the proxy handling the redirect.  if
the proxy is A's outbound proxy, it would get the new invite too.  if
not, there is nothing the provider can do about it, since use of an
outbound proxy is user's own choice.

-- juha